This map illustrates the relative species richness of every tetrad in Wiltshire based on the number of species recorded in that tetrad during the winter season shared fieldwork for Bird Atlas 2007-2011 (BTO 2013) and for Wiltshire Tetrad Atlas 2007-2012.
Between 10 and 88 species were recorded in each surveyed tetrad, with an average of 33.
Species count
Tetrads
1 - 30
426
47%
31 - 45
379
41%
46 - 60
83
9%
61 - 75
24
3%
76 or more
3
<1%
Not surveyed
0
0%